288 FORAMINIFERA OF THE CRAG. 



In the Coralline Crag it has been found in nearly every zone examined. It has 

 also been met with in the Red Crag of Essex, as noted in the First Part of this 

 Monograph. 



Famihj 5.— ROTALID^. 



General Characters. — Test calcareous, perforate ; free or adherent. Typically 

 spiral, and coiled in such a manner that all the chambers are visible on the upper 

 surface, and only those of the last whorl on the inferior or apertural side ; some- 

 times one face being more convex, sometimes the other. Aberrant forms evolute, 

 outspread, acervuline, or irregular. Some of the more highly modified forms 

 have double chamber- walls, supplemental skeleton, and a canal-system. 



Sub-famihj 1. — Spirillinin^. 



General Characters. — Test free, spiral, discoidal, non-septate. Aperture simple, 

 the open end of the tube. 



Genus 1. — Spirillina, Ehrenberg, 1841. 

 Carpenter, ' Itdrod. Foram.,' 1862,^. 180. 



Spibillina, Hhrenherg, Parkerand Jones, Williamson, Carpenter, von QUmbel, 

 Brady, Kilhler and Zwingli, Terquem, Siddall, Berthelin, Mobius, 

 Hausler, Egger, Schaclco, and others. 



Opeecultna, von Reuss. 



CORNUSPIEA, Schultze. 



Ctclolina, Egger. 



1*. Spirillina vivipara, Ehrenberg, 1843, var. minima {SchacJco). Plate VI, fig. 22 



(var. unilinearis, nov., in the explanation of 

 that plate). 



Synonyms of the Type-form : 



PSpiEiLLiNA YiviFAHA, Elirenberg, 1843. Abhaiidl. k. Akad. Wiss. Berliu, vol. for 



184.1, p. 443, pi. iii, Tii, fig. 41. 

 — — [?] — 1847. Ibid., vol. for 1846, p. 446, pi. ii, i, 



fig. 82. 

 Opeeculina punctata, Beuss, 1849. Denksehr. k. Akad. Wiss. Wien, vol. :, 



p. 370, pi. xlvi, fig. 21. 



